Air conditioning systems are in widespread use and are provided in two general arrangements. There are “split” systems where the evaporator unit is located indoors, and the compressor unit is located outside, with refrigerant lines connecting the two units through a wall of the structure. There are also self-contained units that package the evaporator and compressor together in one unit. Some self-contained air conditioning (A/C) systems are designed to be mounted in a window, and other similar A/C units are designed to be mounted in a through-wall opening. A common self-contained A/C unit configuration is the packaged terminal air conditioner (PTAC), which are commonly used in hotel rooms, and similar multi-occupancy structures. As with all A/C systems, the evaporator unit chills air that is drawn or blown over the evaporator coil by a fan, resulting in moisture vapor in the warm air condensing and accumulating on the coil, where it collects and runs into a pan, and drains through a drain hole into a drainage line. In some arrangements, the water is simply routed to an outside port of the PTAC unit, allowing it to drip out. In some applications the cold water is used to cool the condenser coil by routing collected condensate to the condenser portion of the unit, and a fan can splash the water onto the condenser coil.
The high moisture environment inside of a PTAC unit is highly conducive to the growth of certain molds, algae, and other microbial growth. Over time, this growth can obstruct the drain, causing a blockage, resulting in an overflow of water into the interior of the structure, resulting in water damage and potentially giving rise to other forms of mold growth in the building structure. Accordingly, property owners want to avoid the cost of repairs due to water damage caused by overflowing A/C units. This is especially problematic in self-contained A/C units because the drain pan is typically designed to hold some water to cool the coil of the compressor unit.
The problem of microbial growth in PTAC units is treated as a maintenance issue, and to prevent drain blockage from occurring, chemicals are periodically introduced into the drain pan to kill or suppress microbial growth. Chemical treatment is typically accomplished by the use of slow dissolving tablets that are placed in the drain pan. These tablets slowly dissolve in the condensate water, which creates a solution that flows into the drain, killing and inhibiting growth. However, to put these tablets into the drain pan, the PTAC unit must be taken apart by removing the chassis from the wall sleeve in order to access the interior and place the tablets in the drain pan. Although the tablets only need to be added once every several weeks or so, because of the difficulty and inconvenience involved, PTAC units often go untreated for too long, or not at all. It isn't until leakage is noticed that the drain blockage is recognized.
Therefore, a need exists to overcome the problems with the prior art as discussed above.